Project to automatically remove parts from build plate

@MentosZ I decided to just create the topic and tag you in it.



In order to make clearing items from the build plate efficient, the plate needs to be force cooled when the print completes. (For some cases it would be possible to just park the print head and then raise the plate so that it was level with the aux fan. I was playing with that idea before.)
The expansion can be used to control bed cooling fans that cool the bed from above and below with the bed is near the bottom of its travel. This would be the position for ejecting the parts.


When items are cool they self release, at least on the P1P with the textured PEI plate. When I start a print at night, the objects can be pushed off the bed with no effort.

It seems like a dual stepper setup could be used to

  1. slide a wiper arm in along the back of the plate
  2. move the wiper to the front of the plate to clear it

Possible issues

  • the P1P aux fan mount limits access on that side of the machine
  • the wiper travel is limited by the frame of the P1P
  • the way the nozzle load line currently works will need to be modified, as the wiper cannot be guaranteed to remove the thin line

Next Print

Providing a way to repeat the print, or start a new one is required to make auto-clear useful for production.
For a hobbyist the feature can still be useful because I can start a new print manually without going to the printer and removing the print.


Thanks for the initiative :slight_smile:


I suppose you can drive the print bed to a very low position let it cool down (via aux fan or naturally shouldnt matter, we just need to wait for 30°C or so). From there the wiper would be initiated.


I think a single stepper motor setup can be sufficient using a clever rail system with a long lead screw attached to the motor. I will try to prototype a first sketch in Fusion on the weekend.

Next Print

I found myself printing the same thing several times just by using Bambu Handy. This can be the first usecase. Ideally preslicing and sending those sliced files to the cloud server would be possible. This way you could prepare all your files and just start them from your mobile whenever the previous print is ejected. Thanks to the app you should be able to do this from anywhere.

The good thing about cooling is that the “wait for bed temp” g code can be used.

I also use Fusion, so that is convenient. I am in the process of learning how to design using 80/20 aluminum extrusion in Fusion.

I use LAN only mode and never use Handy. I can resend with Studio, but that takes being there. I would like the solution to be able to print multiple copies of a plate overnight.

I also noticed that when printing from the printer menu that it uses the default print settings and not what I selected when sending the print. So if I print from Studio with calibration off, reprinting from the printer turns calibration on. That is not a big issue for now.

I have sent and started a print without using Studio, just using FTP and MQTT to communicate with the printer. That could be used to print multiple times if there was a way for the printer to indicate that it was ready to print again. (Currently, when a print is finished it shows up in Studio as ready, but the print is still on the plate.)

Hello, just received my exentsion board recently and would be happy to join the project. :slight_smile:

I found an interesting video of someone who already created something similiar, maybe it can help us for some inspiration.

I also found these modifications interesteing and could be a good inspiration:

I think the most easy to create and intuitive solution would be something similiar like this from 3DQueue:


I like the idea of the addon for the Ultimaker, it doesnt increase the overall footprint of the printer. Ill try to tinker something like that into the case.

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The ultimaker is similar to what I was thinking of. One stepper positions the wiper at the rear of the plate and the other moves it to the front. That will give me an excuse to redo the mount for the aux fan and get rid of the huge support.

I absolutely love this idea! Hilariously, I have been designing something similar and ended up independently converging on the ultimaker design. I would consider designing for an enclosed P1P as well, which makes keeping identical footprint essential. Also, many people like having bentoboxes in their printers, so that was another complicating factor. I ended up settling on a mount that hides underneath the Aux fan and essentially does what you also envisioned via the ultimaker system.

My current designs in Fusion are very rough so I would love to see what other people make of this.

One potential failure mode is that the parts don’t fully fall off the printbed and then get crushed the next time, but I feel that clever design of the sweeper arm could fully resolve that problem.

Not only the design of the sweeper, but using the bed cool-down temp as part of the process.

I would really like to see your Fusion design.

Yeah, I’d be happy to share–I’ll send it here tomorrow (not at my home computer right now), and if you like, I can invite you to the project folder. And anyone who wants to see files, feel free to DM me your email (heliscone on discord) and I’ll invite you!

Alrighty, I just threw it together again in a new project folder. Here’s a link.

There are motion links set up but I’m not sure if you can adjust them in the browser?

Mainly, I wanted to optimize for usable leadscrew travel, to minimize unsweepable space on the build plate. From there, stepper motor placement became rather difficult, and I ended up placing the stepper right by the top of the aux fan. A belt transfers power down to the leadscrew, via pulley-coupler-leadscrew nut, and the rest is similar to the Ultimaker idea. I recently added the two-part arm, which I thought was incredibly clever by Ultimaker.

Current large issues include:

  1. Overall pulley-coupler length is too long, rendering far too much of the buildplate unsweepable by decreasing the useful leadscrew length. This is an unneeded constraint we could remove with some more careful parts choice.
  2. Interferences galore, but this was basically a first draft, so I expect most of it could be fixed with a better CAD of the P1P and also more careful modelling. I’m going to make a new post asking for a more detailed CAD of the P1P for internal modding.
  3. Similarly, backwall placement and heatbed thickness are not quite accurate, though they are luckily parametric! Reason being that I don’t have access to my P1P at the moment to measure.

I’m not sure if this is the optimal placement at all, and the design is certainly nowhere near polished. But at least you might be able to see some of the challenges I ran into/improve further from here/think up a completely novel and way better solution. And I would love to hear criticism on this design + my slipshod CAD in general, since I’m rather new to design and I’m very eager to improve on both of these!

Hey Heliscone,

thanks for adding me to your project. Looking forward to support you. :slight_smile:

Some concerns and input for the current setup:

  1. I think we should think about using the aux fan also in the setup to be able to cool parts faster. I am not sure if the sweeper wouldnt be better on the other side? But maybe also the aux fan can be placed on the other side aswell.

  2. I will also try to fit the stepper in the case, I think it would make thinks a lot easier if we can fit it. Maybe with a 3d printed mount and locking system this will work.

  3. Can you also draw the two lead srews and stabilisation rods for the Z-axis, since these are basically the stop points for the motion system.

→ I think we need to come up with a clever design that allows the sweeper to move forward bit further and bypass the z rods, otherwise we would loose to much unsweapable area. We could also increase unsweapable are if we mount the system outside of the printer…

  1. We would need to create 3d printed area that forces the sweaper to go down when movin forward and another area that pushes him up again wehn mocing backward.

→ I think this can be done easily when we make some sort of ramps for to move it in potion similiar like in the Ultimaker design with a roof above it.

Cheers Nico

Hi Nico,

Thank you!!I totally agree that we want this to be compatible with aux fan, but the other side also houses the “bento box” air filter that is commonly used, so I was planning on modifying the aux fan mount to go “around” the arm, though I haven’t actually thought through details of how that would work, and this is admittedly a bit of a patchy solution.

I also made a new thread asking for more detailed CAD that includes the z-axis and heatbed, since I’m not with my P1P at the moment so I can’t take measurements. Do you know if such designs exist online? I cannot find them.

Ooh, that is a good point, we could also completely render the over-complex belt system unnecessary by mounting the stepper outside the frame. A first thought for external mounting would be miter gearing to take the stepper outside of the printer’s side, to minimize conflicts with enclosed P1Ps.
But like you say, we’d still have z-axis conflicts… I’m not sure how to get the travel to be fully forward without sacrificing a large deadspace in the rear of the buildplate, did you have ideas on how we could do this?

Also, I think that the rotation of the leadscrew would first lower the arm by rotating the leadscrew nut, and then once the arm is flush against the plate, the leadscrew nut would travel forwards, and vice versa for the return trip.


  1. I suggested using additional fans to cool the plate and monitoring the plate temp with a G code command in order to allow it to cool down so the parts self release.
  2. We should consider whether parts should be internal or external to the case carefully. Having them be internal allows the P1P to be fully enclosed to print hi temp materials. But, it also exposes all those parts to the higher temp. In addition, if we expect the part remover to work with an enclosed P1P then an additional requirement is a way for it to open the door.
  3. do you have a fusion model?
  4. I do not see any reason for the sweeper to move vertically when moving front to back. It should be just above the plate the entire time. We should consider the height of the wiper so that tall parts cannot fall backward over the wiper when pushed at the bottom.

It would be great if BBL could give us a minimal CAD drawing of the P1P. Have you asked them for one?

I have never seen a Fusion model in the browser before. It does not look very usable to me.
Can we create a Fusion Project/Team and share it in Fusion 360?

Yeah of course!! I can share the fusion project with you. :slight_smile:

@Heliscone I have not used discord much and I cannot seem to find you there. My discord user is “.julie777”. Please DM me and help me get started. I am on Discord right now.

I had a chance to load the fusion model and take a look at it. It is a fantastic start. Thank you @Heliscone
I have not looked at all the details.

I do have a few comments based on my cursory view.

  1. I do not understand the two part wiper arm. I would think that an arm that reaches the far side of the plate would be sufficient.
  2. In another project that I looked at, the wiper was a loop around the entire boundaries of the plates. I thought it was ugly. However, once we have a prototype running we might have to consider how to force all parts to move to the front of the plate and fall off, instead of some falling off the sides.
  3. the location of the motor flex coupler is preventing the wiper from dropping at the very back edge of the bed. I think we should reconsider the idea of trying to keep all parts inside the frame volume of the P1P. In general I like that idea, but a P1P in use has an additional required volume behind the frame that cannot be eliminated. That area is primarily a function of the way the power cord plug sticks straight out. The requirement for a place for the poop exit is less restrictive. I have designed all my accessories using a volume behind the printer that gives me a front to back dimension of the printer of 18" (457mm). This dimension barely allows a reasonable bend radius on the power cord. I used this to design my poop chute, my top mounted spool holder. I consider it part of the required space for the printer. Here is my drawing. (I exclude the control panel)

Given the interest in the project, I think we should switch to a GitHub project with discussions, a wiki and have a place to store design files. I think we have enough designers, that separating some of the discussions, etc. will be easier on GitHub. It also provides easier search and organization than a single thread in the community. If everyone agrees then I can just make all of use maintainers of the project.

I went ahead and created the project. If there is a preference that it not be one of my repos then we could create a new GitHub organization. I did not do that because for now it seemed like too much work. (We can change it later.) The other thing to note is that I made the repo private so only those of us in the beta group will be able to access it, after being explicitely added. All I need is your github user names and I will add you as collaborators.

Note: I am not trying to be in control and everything I post is open for discussion. :grinning:

After spending time looking at @Heliscone’s design I also spent some time looking at the printer and playing with a piece of threaded rod to simulate a leadscrew.

I think we should consider starting our design using the right side instead of the left side of the printer.
I have not taken off the back cover and I do not remember the exact layout inside so that might change this.

  • the printer is asymetric. There is more room on the right side of the bed than on the left side. I am not sure what the plastic tab that sticks out to the right of the bed is for but I am ignoring that.
  • anyone with an aux fan will already have the left side occupied.

I do not know if we should consider the possibility of it working on the X1 in our initial design. I have seen no indication that BBL is producing an expansion board for the X1. However, the possibility that some users will have their printer enclosed, or at least have printed side panels is something to consider.

Looking at the printer with the bed at the bottom, it is clear that guide rods and lead screws constrain the design. I did notice that the area above the middle frame rail has room below the belt/Y axis that is clear from front to back with a dimension longer than the Y dimension of the plate. Of course camera and LED may occupy this space on the left side, but the right side is clear.

Does anyone have enough experience with stepper motors to have an idea what size could be used? If we could use a NEMA 11 it would save quite a bit of space over the common NEMA 17.

Ah, github’s a terrific idea and seems excellent, I DMed you my github info.

The initial thinking behind two part arm is that it can be stowed vertically underneath the bar (middle frame rail), whereas a full-length arm would need some cutouts to fit fully, at least that was my impression. I could definitely have made a mistake in the initial sketched out design.

At first I was hesitant to use the right side, but given that BentoBoxes are way less commonly used than Aux Fans, plus the additional free space on the right, I agree that working in the printer’s right side is better.

I am 100% for compatibility with the X1 if we can manage it, since a stepper can also be controlled remotely with an ESP32/HomeAssistant. My P1P is enclosed, and although I am open to making additional cuts in the acrylic panel to house our sweeper, I’m not sure if X1 users want to break out the dremel. :laughing:

Also, regarding steppers, I am certainly not an expert, but I did find NEMA8 motors that are even lower profile:

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